Ultrasonic transducers have been employed in ultrasound therapy systems to achieve therapeutic heating of diseased and other tissues. Arrays of ultrasound transducers operating to form a beam of ultrasonic energy cause a conversion of sound to thermal energy in the affected tissue areas or treatment volumes, and a subsequent beneficial rise in the temperature in the treatment volumes. With proper monitoring of the heating effect, ultrasound therapy systems can be used to treat harmful cells and to controllably destroy cancerous tumors.
As known to those skilled in the art, ultrasonic transducers are constructed and operated to take electrical power and produce ultrasound energy waves from a surface of a transducer element in a process generally referred to as transduction. The nature and extent of the transduction depends on the material used to construct the transducers, transducer geometry, and the electrical input to the transducers. A common material used in construction of ultrasound transducers is piezo-electric transducer crystal material, e.g., lead zirconate titanate (PZT).
One challenge in constructing clinically-usable systems for image-guided therapy is in constructing the electrical, mechanical, and electro-mechanical support systems for providing thermal therapy to a patient. This is especially true if part of the system needs to reside in an environment having strong magnetic fields such as is found in magnetic resonance imaging (MRI) environments.
It is useful to have a controllable and sterile system for controlling a temperature of a therapy device in a patient during a thermal therapy treatment procedure.